Physics · 2017
JEE Main · 9 April 2017, Shift 1 · Q24
A Laser light of wavelength 660 nm is used to weld Retina detachment. If a Laser pulse of width 60 ms and power 0.5 kW is used the approximate number…
A Laser light of wavelength $\displaystyle 660$ nm is used to weld Retina detachment. If a Laser pulse of width $\displaystyle 60$ ms and power $\displaystyle 0.5$ kW is used the approximate number of photons in the pulse are :
[Take Planck's constant $\displaystyle \mathrm{h}=6.62 \times 10^{-34}$ Js]
Official answer
(1)
$\displaystyle 10^{20}$
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JEE Main 2017 Physics question, with the answer from NTA’s final answer key. Where our answers come from.